Well, for you woodworkers with reasonably flat workshop floors, General has
come out with the HoverPad. It's a mobile base for heavy machine tools based
on Hovercraft technology.
I was at the Toronto Woodworking show last weekend to take part in the
premiere presentation of their new line of Access machine tools designed for
people in wheelchairs, who like to sit or who are of lower stature. While
there, I had a good look at their HoverPad. Essentially, you can push
hundreds of pounds of machine tool around with one finger. I can think of a
dozen uses for one of these. They're not much more expensive than other
decent mobile bases, can be cut to size and can be run on really low end
So for those of you interested, here's the specs and a video.
If I remember properly, it's somewhere around $250 CA. I'm sure they will
give you exact prices if you email them. I actually giggled while I was
pushing around a huge tablesaw within a confined area while peppering the
General company president with technical questions about the HoverPad. Being
a wheelchair user myself, I can think of dozens of applications for this
device, none of them having anything to do with woodoworking. The health
industry will flip on it's ear when it hears about this.
Anything online for the Access tool line?
I've been told that the prices for the 5 Access line woodworking machines
are the same as the regular line. That itself is great news since sales
figures will take considerable time for them to truly make a profit out of
I dug around a bit more and found $170 for the small and $250 for the
I can believe it! The folks in the video look like they're having a good
I'm out of my wheelchair now, but still need it for long distances and
anything that requires standing without leaning on something - a
tablesaw, for example.
Now I need to figure out the best way to mount everything to minimize the
number of pads needed.
Lots of places will flip.
Yeah. Normally the prices would be higher. Just like "computer" furniture
that one word adds 40% to the price.
Thanks for that, I couldn't seem to find it.
May I ask what kind of chair you use? Insurance paid for a rental for me
for a year and then the provider said it was mine. But, it's too heavy
for me to wrestle into the truck - an invacare, blue seat and lots of
chrome model. I'm looking for something light weight - <30# or so.
Could be a possibility as long as one doesn't mind risking their $1000-$3000
pieces of machinery on some plywood, nuts, bolts and painter's drop sheets.
Of course, it's unlikely that machinery would tip over or anything, but it
would definitely be a jury rig setup and subject to problems.
It's a great idea, but I have questions about what happens to the
exhaust air. Some of it will escape along the floor level, and
wherever else it exhausts, and blow sawdust everywhere. Your typical
less-than-exemplary-housekeeping shop would probably present
problems. To move the machine you'd have to do a choice cleanup, move
the machine, then wait for the dust to settle before you can breathe
The manual says to have the area around the machine clear of dust and
debris...how far around and how clear? You don't need a floor you can
eat off of with a wheeled mobile base, just clear the bigger stuff out
of the way, and it doesn't matter how much crud is on top of the base.
Seeing that they were running it from a small air tank, I assume the
volume of air actually escaping is pretty low. Once the physics get it
up and floating, you just need a dribble of air to keep it there. They
show a small amount of dust being displaced along the edge on one of
the close-ups and you can see it is not blown but a few inches to the
Plus, they say it can be cut to shape. That is really cool. Looks like
a great packaging of an existing idea. I'd say watch for Craftsman and
Grizz to have the mass market and low cost versions out soon.
Have you ever used compressed air to blow out a tool? That's only
using a small volume of air. It's the pressure which translates to
speed. Of course they're not going to show clouds of dust being blown
about in a promotional video because it would kill half of the market
on the spot. Like I said, it's a nifty idea, but it's problematic in
a working woodworking shop unless you have a shop like in one of the
Good incentive for an inveterate slob like me
to change his habits. Cleaning one's work area
frequently is a very good practice. Aside from the
immediate safety aspect, it is a good excuse
to take a break and plan the next operation.
OTOH when turning there is certain charm to standing
in the middle of huge pile of chips.
On Sun, 09 Mar 2008 08:47:34 -0500, Upscale wrote:
I think the major issue applies to the Pro and homebuilt versions -
Yes, you can get it moving at some speed by pushing it with a single
finger for a while. *But* when you realise it's heading for somewhere you
really don't want it to go you have to apply thew same force for the same
time to stop it. Or in the likely event of wanting to stop it 10x quicker
than that, multiply the force up by x10 too...
The principle behind these isn't new, but this one has to be the flimsiest
design that I've ever seen.
Boeing has been designing and using hover pads to lift and move aircraft
sections into position since WWII. In fact, Boeing formed a subsidiary to
manufacture commercial versions of these for sale. They come in all sizes
(and cost), but the commercial ones are far too expensive for small shops
and hobbyists. A version was available some years back for use under
refrigerators, to be powered by a vacuum cleaner whenever the lady of the
house wanted to clean behind it, but I don't know if they are still
available. If you can find one it would likely be a cheap way to move your
Using only one large air chamber in the design produces a very tippy and
unstable unit that would not be very suitable for moving machines (remember
the hover craft show on Myth Busters?). If you look closely at General's
hover pad you will see that it is composed of many small hover pads. The use
of 3 or more give the platform the needed stability. In use, the pad only
needs the thinest of air film between the skirt and the floor for it to
work, but with only a very thin film of air, the floor has to be very
smooth. Increasing the air flow to increases the thickness of the air film
and will allow it to pass over less than perfect floors, but any significant
void in the floor surface will cause all of the air to leak out of the
affected chamber and the pad will bottom out and drag. In other words, they
will work great on a tile or concrete floor, until you try to cross over a
crack or other significant irregularity in the floor surface that the skirt
can't seal. When the air leaks out faster than it's coming in, the pad will
bottom out. A platform with 3 or 4 chambers under it will provide even
lifting and stability. Boeing makes single chamber pads, but they are
intended to be used in groups of 3 or more to distribute the load and
provide the needed stability. It's amazing how much weight they can lift and
move. 4,000 pounds can easily be moved using only 4-8 inch diameter pads
with only 6-11 pounds of air pressure. More air pressure raises the pad
slightly higher, allowing it to cross slight imperfections in the floor more
easily but it isn't necessary for most use, and it wastes a lot of air. It
doesn't take much air loss for the pad to collapse.
I have made some strong and reliable pads by gluing small new lawn tractor
inner tubes to 3/4 thick birch plywood (tractor tubes are available with
center holes as small as 4" dia and overall diameters of about 8"). The air
path for my pads is similar to the one in the link above, where the air
first enters the tube and then exits the tube into the center "hub hole" of
the tube, where it then leaks out between the bottom of the tube's surface
and the floor, forming the "air bearing". You will need to buy new tubes for
this project as their shape needs to be flat and not all stretched out of
shape, so they can be easily glued to the plywood. I use a wide ring of
automotive door gasket cement to bond the inner tube to the plywood and then
place a concrete block on top as a clamp "until the glue dries". The regular
filling stem is cut off and the resulting hole in the tube is glued to the
plywood so that it is in line with the air entrance hole (glue it well - no
leaks allowed around this point). Using a razor knife I then cut 4 slits
about 1/2" long around the center of the tube to allow the air to escape
from the inside of the tube into the center chamber, similar to the design
in the link above. Using rubber tractor inner tubes makes the pads survive
much longer than the 6 mil plastic, as small scratches from a rough floor
surface (pebbles, etc.) won't immediately tear the rubber like it will the
plastic. Many years ago I made some out of hemorroid cushions, but the ones
that are available now aren't very well suited for this. The old ones were
made from a vulcanized canvas material and the ones that are available now
are made of thin vinyl. (I got strange looks from the drugstore cashier
when I bought 4 at the same time - nobody gives you a second look when you
want to buy 4 inner tubes). I use my 18 cfm shop air compressor to power
them, with an air pressure regulator and hose connected to each pad (this
lets me vary the pressure and flow to one pad at a time) and my pads are all
made separate so I can put one under each corner, leg, etc. of whatever I
want to move. I can use 3, 4, or more if necessary (my compressor won't
likely handle more, but that's the plan). For a table saw or other small
machine 3 or 4 pads mounted on a board that's large enough to carry the tool
would work out fine. In a large commercial cabinet shop it would be handy to
have them separate so they could be placed under each corner of a very large
cabinet, etc. for movement around the shop floor.
Once up "on air" your tool will move very easily, so easy in fact, that you
will need to be careful not to get it moving too fast, or you may not be
able to stop it. It will stop very quickly if the air is shut off, but in a
one-man shop you won't have enough hands to hang on and shut off the air
How clean does the area around the saw have to be and how much dust
gets kicked up? You mentioned ~10 PSI for the Boeing thing, what do
you run yours at?
The hemorrhoid cushion part was hilarious. Reminded me of a cyclist
buddy telling me about shopping for support hose to help with his
varicose veins and having the clerk in the lingerie department give
him odd looks when he asked for a pair in his size. ;)
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